1. Field of the Invention
The present invention relates to a photoluminescent golf ball which can be clearly visualized at night as well as during cloudy or low light conditions. The photoluminescent golf ball has excellent physical performance characteristics and exhibits an extended duration of luminescence under night or low light conditions. More particularly, the present invention relates to a photoluminescent golf ball which can be easily seen both in flight and on the course due to its clear luminescence. In comparison to conventional luminescent golf balls, the balls of the present invention demonstrate superior driver distance, durability, persistent luminescence, and improved shelf life.
2. Description of the Prior Art
The sport of golf has become extremely popular. In recent years, the rise in popularity of international, professional players has contributed to the popularity of the sport in many countries that have not historically been associated with the sport. To accommodate the increased number of golfers, personal schedules, or time preferences, golf is occasionally held after sunset or before sunrise under artificial course lighting. In these times, although there is lighting, it is difficult to visually follow the golf ball's flight after tee shots or fairway shots because of the low light. Frequently, the golf players cannot find the golf balls, creating course delays. Such delays are costly to the course operators. Further, lost balls are both an unwelcome expense and a frustration for the golfer who incurs a penalty for a lost ball.
To solve these problems, there have been developed golf balls which comprise luminescent compounds which glow following exposure to U.V. or other light. However, most of the conventional golf balls developed for night games are disadvantageous in the following aspects. When the luminescent compounds are coated on golf balls by spraying, the compounds are not durable and wear off during play. When certain luminescent compounds, such as Al2O3 based photoluminescent materials, are mixed with a cover resin, a large amount of the compounds are needed, deteriorating the strength of the resulting golf balls.
In addition, conventional luminescent compounds are weak in brightness, chemical resistance, and weather resistance, as well as showing a short luminous time period. Accordingly, conventional luminescent golf balls suffer from the disadvantage of poor strength and short driver distance. Further, the photoluminescent pigment used in many conventional golf balls are highly alkaline and are thus vulnerable to moisture damage and promote the aging of the resin of golf balls, thus reducing the life span of the golf balls.
Another prior art ball uses a clear, solid golf ball construction with a quarter-inch diameter hole defined through the ball, whereby a night light stick of about a quarter-inch diameter is inserted to artificially light the ball. This type of ball causes improper balance, thus affecting the ball's flight symmetry while also yielding shorter flight distance performance. Accurate putting is also impaired by the off-balance ball. The light stick is replaced with a new stick once the luminescence fades.